Exam 1

1. Metainformation

   Tag	Value
   file	Assumptions_uu-linearity-001-en_uu-linearity-001-en
   name	uu-linearity-001-en
   section	Assumptions/Linearity
   type	schoice
   solution	FALSE, FALSE, FALSE, TRUE
   Type	Interpreting graph
   Program	SPSS
   Language	English
   Level	Statistical Literacy

   Question

   The scatterplot below is part of a study among MBO students on the relationship between the amount of supervision from on-the-job trainers (X-axis) and students’ development of independence (Y-axis).

   Taking this scatterplot as a starting point, which assumption was clearly violated when analyzing the linear regression of guidance on independence?

   

   
   
   1. FALSE: Homoscedasticity
   2. FALSE: Interval measurement level of dependent variable
   3. FALSE: Multicollinearity
   4. TRUE: Linearity
   
   

   Solution

   This figure shows that the linear solution has an explained variance of .24 (= $R^2$). However, the quadratic solution is better, with an explained variance of .31 (= $R^2$). This is actually higher, so the relationship between guidance and self-efficacy is seemingly not linear but quadratic. This violates the assumption of linearity.